I'm having a heck of a time using a MAX3221 with my design. Eagle refuses to route anything to it. I assume it's a signal path size issue and Eagle thinks the connections will be too large for the pins but changing various design rules doesn't seem to help me.

You can create a Grid alias. Basically set the grid the way you want it. Then right-click on the Grid icon (it's at the very top, right under the Open one), select New and give it a name. Now regardless of what you're doing, regardless of what the current grid is, you can right-click on the grid icon and select the one you created. Voila. You can do this both for the board and schematic views.

You can create a Grid alias. Basically set the grid the way you want it. Then right-click on the Grid icon (it's at the very top, right under the Open one), select New and give it a name. Now regardless of what you're doing, regardless of what the current grid is, you can right-click on the grid icon and select the one you created. Voila. You can do this both for the board and schematic views.

That was easy! Does the grid name and setting follow the project or does it set the grid the same way every time you open Eagle?

It's saved with the program settings. Next time you open Eagle, just right click on the Grid button and select your default before you start doing anything. I have a few different settings this way for different purposes.